Fluidic device



Sept. 30, 1969 Filed June l. 1966 R. F. OKEEFE FLUIDIC DEVICE Jay? 4 Sheets-Sheet 2 INVENTOR,

TTOENEY R. F. OKEEFE FLUIDIC DEVICE sept. 3o, 1969 4 Sheets-Sheet S Filed June l, 1966 IMQ. \m mm Kms. S@ @nl wwwa: QW h.. Kfm .IHQN \\\\m\l\`\\ .\\.n1\ llmn, www M E0 x am d X. @n M i 1 .Qq Y w vw sw AWN* ,w Xmmu wv .www [www wu. E w I, vt. mq mmm, QM, www. ww. @nu A. mv NN g .wn NSM Q A m* 147' TEA/EY R. F. OKEEFE sept. 3o, 1969 FLUIDIC DEVICE 4 Sheets-Sheet 4 Q SNN Filed June 1. 1966 United States Patent O 3,469,593 FLUIDIC DEVICE Robert F. OKeefe, Trumbull, Conn., assignor to Pitney- Bowes, Inc., Stamford, Conn., a corporation of Delaware Continuation-in-part of applications Ser. No. 436,411, Mar. 2, 1965, Ser. No. 451,377, Apr. 28, 1965, and Ser. No. 471,164, July 12, 1965. This application June 1, 1966, Ser. No. 554,463

Int. Cl. Fc 1/18 U.S. Cl. 137-815 50 Claims ABSTRACT OF THE DISCLOSURE In turbulence type iiuid amplifiers, one ore more of the following features can be included to improve and/or modify the operation of such amplifiers, namely: switching the amplifier to its laminar ow condition by applying a control signal at a point upstream from the downstream end of the emitter of the amplifier; causing a portion of the energy in the turbulent mainstream to be fed back through the amplifier interaction chamber so as to maintain the amplifiier in its turbulent flow condition; utilizing an off-set low pressure region in the interaction chamber and a plurality of selective operable uid control jets; and most importantly, providing a common guide surface along which both laminar and turbulent fluid flow may take place in iiowing through an enlarged interaction chamber.

This application is a continuation-in-part of my three copending applications Serial No. 436,441, filed Mar. 2, 1965, and now abandoned for Fluid Amplifier; Serial No. 451,377, filed Apr. 28, 1965, and now abandoned, for Fluid Amplifier; and Serial No. 471,164, filed July l2, 1965, and now abandoned, for Fluid Amplifier.

This invention relates to a uidic device that has a novel arrangement of fluid conducting passages therein. More particularly the invention relates to a novel fluid control device which is constructed so as to function in accordance with a novel combination of fluid ow phenomena.

Conventional types of uidic devices are illustrated by U.S. Patents 3,111,291 (Horton), 3,234,955 (Auger), and 2,408,603 (Braithwaite et al.). In the Horton patent a stream defiection and wall attachment effect is a primary operational characteristic associated with the uid flow occurring in the interaction chamber of the described device, there being no operative combination of laminar and turbulent uid fiow conditions utilized here. In the Auger patent the shifting between laminar and turbulent uid iiow conditions is a primary operational characteristic associated with the flow conditions existing in the region between the emitter and the collector, there being no substantial deection and Wall attachment effect utilized in the described device. In the `Braithwaite et al. patent a lateral deflection of the fluid jet, is a primary operational characteristic associated with the fiow existing between the fluid emitting and receiving tubes, there being no Wall attachment effect or operative combination of laminar and turbulent ow conditions used in the described device. Thus although each of these three known uidic devices has its own particular operational characteristics and associated advantages and disadvantages; any one of these three types of devices does not possess the primary characteristics and/or advantages of both of the other two. The instant invention contemplates a novel construction and arrangement for a uidic device which in operation sets up a uid system that includes all three of the abovenoted ow phenomena, namely a wall interaction effect, an operative combination of laminar and turbulent fluid ICC flow conditions, and a jet deflection characteristic, which fiuid system greatly improves the practicality, reliability and general efiiciency of a fluidic device.

Conventional turbulence type amplifiers, as exemplied by that shown in U.S. Patent No. 1,160,072 ('Hall), are usually provided with an emitter, a collector and a signal control means. In the operation of this type of fluid device a laminar uid jet issues from the emitter and is at least partially received by the collector. Upon initiation of an appropriate signal by said control means the laminar uid ow normally received by the collector becomes turbulent with the result that the impact or uid recovery pressure existing in the collector is measurably reduced. Upon termination of said signal a laminar iiow condition is immediately re-established in the main uid stream issuing from the emitter and the fluid recovery pressure in the collector is immediately increased. This monostable type of fluid amplifier may thus be shifted from a normal laminar mode of operation to a turbulent mode of operation and then back to said normal mode by the application and removal respectively of an appropriate fluid or other type of control signal. Inherent in the operation of such turbulence type amplifiers is the generation of sonic waves some of which move out laterally with respect to the general longitudinal direction of the main iiuid jet or stream leaving the emitter. These sonic waves, if reected by surrounding structure, may be thereby inadvertently redirected back against the side of the main fluid stream leaving the emitter and this action tends to cause the laminar ow in said stream to become turbulent or at least be less resistant to a change to such turbulent iiow. Under these conditions conventional type turbulence amplifiers may have a low level of operational stability and/ or may be susceptible to being shifted from one operational mode to another by random impacts or other types of shock loads. For example when a conventional type of turbulence amplifier is subjected to the combined effects of the above mentioned reected sonic waves and random external vibrational and/or impact loads it is quite possible to arrive at a condition where the amplifier shifts from a laminar to a turbulent ow state without the application of the usual required control signal. This possibility is of course highly undesirable particularly where an amplifier is being used in a logic or control circuit. The instant invention further contemplates a means for significantly improving the stability, reliability and other operational characteristics of a turbulence type uidic device.

When, during the normal mode of operation of a conventional turbulence type fiuid amplifier, no control signal is imposed on the amplifier a position or a relatively high fluid output pressure is establised in the collector, and when a control signal is thereafter applied a negative or relatively low fiuid output pressure is established in said collector. This type of operation, i.e., obtaining a positive type or higher pressure output when no signal is applied and a negative type or lower pressure output when there is a control signal applied, may be desirable for certain applications. However there are many situations where it is convenient to have a control unit exhibit. ing a negative type output when no signal is applied and a positive type output when there is a signal applied. This latter type of operation can be obtained by coupling two or more conventional turbulence type amplifiers in a cross-over type of circuit however this of course adds to the cost and the uid consumption of such a circuit. The instant invention further contemplates the provision of a single turbulence type amplifier that will inherently afford said latter type of operation.

Conventional turbulence type amplifiers are usually -rnonostable in operation, i.e. a change from the normal operative condition of the amplifier is obtained only as long yas a signal remains applied by the control means. This type of operation may be satisfactory for certain applications however in many instances it is high- 1y desirable to have a bistable type of operation whereby either of two stable pressure or flow conditions may exist in the output line of the amplifier and whereby the fluid pressure or flow in said output line will, when in either operative condition, remain in that condition until changed to the other pressure or flow condition by the momentary application of an appropriate control signal.

One object of the instant invention is to provide a novel wall and jet interaction device which affords greatly improved operational characteristics and efficiencies Another object of the invention is to provide a novel fluidic device wherein a laminar fluid jet is caused to become turbulent and to interact with a laterally disposed guide wall or surface.

Another object of the instant invention is to provide a novel fluidic device wherein a laminar jet of fluid is caused to become turbulent and substantially deflected so as to become attached to or to interact with an adjacent guide wall surface.

Another object of the invention is to provide a novel fluid device wherein the region between a fluid emitter and an aligned fluid collector is substantially enclosed and is provided with a venting means and fluid flow guide surfaces which at least partially guide the fluid flow through said region to said venting means.

Another object of the invention is to provide a novel wall and jet interaction device having an emitter and a collector that are effectively spaced relatively close together to obtain a high power recovery, and having interaction fluid flow guide walls which effectively permit the creation of low fluid pressures in the region adjacent said emitter whereby a significant reduction in the power required for the controlling of the instant device is possible.

Another object of the invention is to provide a novel construction and arrangement for a fluidic device that utilizes an improved operative combination of laminar and turbulent fluid flow conditions.

Another object of the invention is to provide a novel configuration for a substantially enclosed interaction chamber located between an emitter and an axially aligned collector of a fluid amplifier.

Another object of the invention is to provide an improved construction for a turbulence type of fluid arnplifier whereby the tendency for the amplifier to shift from one operational mode to another due to sonic and/ or shock loads is minimized.

Another object of the instant invention is to obtain higher switching speeds and/or operational efliciencies in a turbulence type fluid amplifier by improving the construction and arrangement of the elemental parts of the amplifier and by utilizing a wall attachment o1' interaction effect.

Another object of the invention is to provide a novel turbulence type fluid amplifier wherein a positive type fluid output is obtained from the application of a control signal to said amplifier.

Another object of the invention is to provide a novel fluid amplifier wherein a better signal to noise ratio is obtained, and wherein the pressure in the collector is comparatively low when a turbulent fluid flow state exists.

Another object of the invention is to provide an improved fluid amplifier wherein at least some of the sound waves normally generated by a main laminar fluid stream are controlled so as to be prevented from adversely affecting the stability of the main laminar fluid stream of the amplifier.

Another object of the invention is to provide an improved fluid amplifier having a means for shielding critical fluid flow regions from sound or sonic waves emanating from external sources.

Another object of the instant invention is to provide a novel turbulence type fluidic device that exhibits a reliable bistable type of operation.

Another object of the invention is to provide a novel fluidic device which is constructed and arranged so that when operating in a turbulence mode a portion of the energy in the main fluid stream is fed back so as to maintain the turbulent flow conditions in said main stream after the termination of the usually externally applied control signal.

Another object of the invention is to provide a novel fluid amplifier having a novel asymmetrical interaction chamber formed between an emitter and a collector.

Another object of the instant invention is to provide a novel fluid amplifier having one operative output line and two operative control lines, the latter respectively shifting said amplifier back and forth between its two modes of operation.

A further object of the invention is to provide a novel bistable fluid amplifier having a fluid flow guide surface formed therein and to which at least a portion of the fluid issuing from the amplifier emitter may attach itself as long as the amplifier is operating in its turbulent mode.

Many other objects of the invention will become apparent as the disclosure progresses.

In the drawings:

FIG. l is an axial sectional view illustrating the construction and arrangement of the parts of one of the instant fluidic devices.

FIG. 2. is a cross sectional View taken along section line 2-2 of FIG. 1.

FIG. 3 is a cross sectional view taken along section line 3-3 of FIG. l.

FIGS. 4, 5 and 6 are diagrammatic sketches illustrating certain operating conditions associated with the instant type of fluidic device.

FIG. 7 is an axial sectional view illustrating the construction of an alternate type of fluid amplifier having some of the structural and operational features shown and described in connection with FIG. 1.

FIG. 8 is a cross sectional View taken along section line 8-8 of FIG. 7.

FIG. 9 is an axial sectional view illustrating another alternate type of turbulence amplifier having some of the structural and operational features shown and described in connection with FIG. 1.

FIGS. 10 and 11 are cross sectional views respectively taken along sections lines 10---10` and 11-11 of FIG. 9.

FIG. l2 is a plan view of the grooved plate forming part of a novel wall and jet interaction device.

FIG. 13 is a cross sectional view taken along the longitudinal section line 1313 of FIG. l2.

FIG. 14 is a cross sectional view taken along the transverse section line 14-14 of FIG. 12.

FIG. 15 is a cross sectional view taken along the transverse section line 15-15 of FIG. l2.

FIG. 16 is a plan view similar to FIG. l2 and illustrates an alternate groove configuration for the interaction chamber of the device of FIG. 12.

FIG. 17 is a plan view illustrating the groove configuration in the main plate member of a bistable type fluidic device.

FIG. 18 is a plan view illustrating the assembled construction of the fluidic device generally illustrated in FIG. 17.

FIG. 19 is an end View of the apparatus shown in FIG. 18.

FIG. 20 is a cross sectional view taken along the transverse section line 20-20 of FIG. 18.

FIG. 2l is a diagrammatic view illustrating the specific configuration of one of the interaction chamber side walls of the amplifier of FIGS. l7-20.

Referring to FIGS. 1-3 there is shown a main body member 10 that is formed with an elongated axial bore 11. A tubular insert 12 having a smooth bore 13 formed therethrough is disposed in said bore 11 and is secured by any suitable means to the body member 10, the insert being yadapted to be coupled by any suitable means to a fluid pressure supply means 14. The inner end of the tubular insert 12 is axially spaced from the inner end of the bore 11 so as to thereby establish a cylindrical control chamber 16. The downstream end of the main body is formed with an axially tapered recess 17 which is defined by the divergent flared diffuser surface 18 and which communicates at its reduced upstream end with said control chamber 16 through a discharge orifice 20, the cross sectional area of orifice 20 being less than that for the chamber 16. A pair of radially extending exhaust ports or vent holes 21, 22 formed in the main body 10 communicate with said tapered recess 17. The downstream end of the main body 10 is also formed with a threaded counter-bore 23 into which is threaded a support member 24 that is formed with an axially extending tapered projection 25. The projection 25 extends substantially coaxially into the tapered recess 17 so that its inner end is located well within said recess and only a short distance downstream from said orifice 20. The support member 24 is formed with a suitable axial bore in which is secured a tubular fitting 26 that has bore 27 formed therethrough. The inner end of bore 27 communicates with the inner axial region of recess 17 through a small bore 30 formed in projection 25 while the outer end of bore 27 is effectively coupled with a pressure responsive device, a circuit or other means 31. The walls forming the bore 13, the chamber 16, the orice 20 and at least the inner end of recess 17 define the emitter of the instant turbulence type amplifier while the walls forming the bores 27 and 30 collectively define the collector of the instant amplifier. Said bores 13, 30 and 27, the chamber 16, orifice 20 and recess 17 are all substantially coaxially disposed.

A signal control means is provided for the amplifier of FIGS. 1 3 and comprises a small radially extending bore 32 which communicates at its inner end with the control chamber 16 and at its outer end with a bore 33 formed through a tubular fitting 34. The fitting 34, which is secured by any suitable means in a corresponding bore formed in the main body member 10, is pneumatically coupled at its upper end to a flow control means 3S that is provided with a venturi constriction 36 in a fluid conducting passage 37 formed therethrough. The venturi constriction 36 and the bore 33 effectively define an aspirating arrangement whereby when a fluid flow 38 is established through passage 37 there will be a tendency to induce a fluid flow from bore 33 into passage 37 and hence a flow of fluid through bore 33 and into chamber 16 occurring during operation of the instant amplifier will be effectively opposed or restricted.

The physical size of the instant amplifier is quite small; for example one unit which has been successfully operated was provided with a chamber 16 having a diameter of approximately .060 inch, an axial length of 5%,2 inch, and an orifice 20 having a diameter of approximately .020 inch. In this particular amplifier the diameter for bores 13 and 30 was approximately .020 inch while the diameter of bore 32 was approximately .007 inch. It will be understood that these dimensions are listed for illustrative purposes only and are not to be construed as restrictive in nature. It will be further understood that two or more of the various elemental parts of the instant amplifier, such as 10, 11, 34, 35, 24 and/or 26 may be made integral thereby simplifying the production of these amplifier units using known processes such as molding, die casting, etching, etc.

Considering the operation of the amplifier of FIGS. 1-3, fluid under pressure from supply means 14 will flow through bore 13 across chamber 16 and out through the orifice 20. This fluid flow would normally be laminar so that most of the laminar fluid jet issuing from the discharge orice 20 of the emitter Would be received by the collector bores 30 and 27, however with the provision of the bores 32 and 33 the chamber 16 is normally open to the fluid conditions existing in the venturi 36 and when no signal fluid flow 38 exists in the passage 37 the chamber 16 effectively communicates with the surrounding atmosphere. Under these conditions then the said laminar fluid ow through chamber 16 induces a fluid flow through bores 33 and 32 and into chamber 16 and this induced flow of fluid is entrained with the main flow of fluid from the source 14, this entrainment thereby causing the fluid flow in the chamber 16 and also the ow issuing from the orifice 20 to become turbulent. It will be apparent here then that with no fluid signal or flow 38 applied to the control means 35 the instant amplifier will normally operate in its turbulent flow state, a mode wherein a reduced pressure exists in the collector passages or bores 30 and 27.

When a fluid control signal or flow 38 is established in the passage 37 the aspirating effect thereby produced in the bore 33 by the venturi 36 inhibits the above noted normal flow of fluid into the chamber 16 through bore 33. This effective valving action thus prevents any fluid entrainment by main axial fluid stream in chamber 16 and hence the fluid flow in said chamber and in the jet issuing from orifice 20 becomes laminar and remains laminar as long las the fluid control signal 38 remains applied. Simultaneously here the fluid pressure in the collector will become significantly higher. When the control signal 38 is interrupted the above noted fluid entrainment by the main stream in chamber 16 again occurs and thus the amplifier automatically reverts to its said normal turbulent operating mode.

From the above description it will be evident that an increase in pressure in the collector is experienced when a control signal is applied and that a collector pressure decrease is experienced when the control signal is removed. This action is generally opposite from that of most conventional turbulence amplifiers. The proportion of fluid exhausting through ports 21, 22 at any given time will be governed in large part here by the nature of the means 31 downstream from the collector.

As was previously mentioned the instant amplifier is constructed so as to have a greatly improved stability of operation and so as to be far less susceptible to faulty shifts in operating modes due to the presence of mechanical impact loads, sonic waves, and/ or vibrational effects. The provision of the flared diffuser surface 18, particularly that part of said surface that is generally located between the emitter orifice 20 and the upstream end of the collector bore 30, affords two very significant advantages. First the operating effects produced by this diffuser surface will improve the stability of any laminar flow of fluid that exists between the emitter orifice 20 and collector bore 30. The reason for this improvement may be seen with reference to the diagrammatic sketches in FIGS. 4 and 5. As illustrated in FIG. 4 any laminar fluid stream 40 may generate laterally moving sound waves 41 which can be reflected by an adjacent surface 42 back into the laminar stream 40 therebytending to induce a turbulent flow in said stream, or, if not to produce an actual turbulent flow, to weaken the stability of said laminar flow thereby increasing the latters susceptibility to inadvertently becoming turbulent by reason of the imposition of mechanical shock loads, etc. If, as illustrated in FIG. 5, a curved flared surface 42a is provided the said laterally moving sound waves will be controllably redirected as indicated at 44 so as to avoid being reflected back into the stream 40 and hence the latter can remain in a laminar state and be most stable and resistive to mechanical shock loads and the like. Thus in the laminar mode of amplifier operation the flared surface 18 will tend to prevent the laterally moving sonic waves from interfering with the laminar fluid flow between the emitter orifice 20 and the collector bore 30.

The second significant advantage afforded by the provision of the diffuser surface 18 is the greatly stabilized turbulent fluid flow condition when the amplifier is operating in its turbulent mode. As is generally illustrated in FIG. 6 any fluid flow 50 tends to attach itself to, as at 51, or to at least follow along a surface such as 52 defining a gradually diverging fluid conduit. As will be apparent this genera-l characteristic of flow will, as applied in the instant amplifier, tend to cause the fluid stream issuing from orifice to follow along the diffuser surface 18 when the amplifier is in the said turbulent mode. This flow-surface attachment tendency which is apparently caused by a boundary layer effect not only makes the turbulent flow more stable but also tends to cause a further decrease in the output pressure existing in the collector of the amplifier due to the divergence of the fluid flow. This latter condition will produce a wider and more uniform pressure difference in the collector when the operational mode shifting of the amplifier occurs a-nd hence the signal to noise ratio of the pressure output in the collector of the instant amplifier is significantly improved. The two above described advantages afforded by the provision of the diffuser surface 18 allows the upstream end of the collector bore 30 to be placed much closer axially to the orifice 20 of the emitter than previously and this in turn permits significantly higher switching speeds to be obtained in the instant amplifier.

It was mentioned above that the laterally moving sound waves normally generated by a laminar fluid flow are controllably redirected by the flared surface 18. It is desirable to conduct these redirected sound waves away from the unit and/ or to absorb them so that they cannot interfere with the desired stable functioning of the amplifier. To this end a soft annular piece of sponge-like flexible cellular or porous material 53 is mounted near the effective downstream end of the diffuser surface 18 so as to be in a position to receive and absorb the said redirected sound waves. This porous material 53 will also advantageously inhibit the entry of sound waves and the like from external sourcesinto the region between the emitter and collector.

The tapered diffuser surface 18 may be generally bell shaped or even conical; the particular shape for any given amplifier being governed at least in part by the configuration of the other elements of the amplifier.

The turbulence amplifier illustrated in FIGS. 1-3 has two general distinguishing characteristics namely the provision of .a fluid entrainment chamber 16 upstream from the emitter orifice 20 and the provision of a flared diffuser surface 18 immediately downstream from said orifice 20. These two general features may be utilized individually in turbulence type amplifiers and FIGS. 7-8 and 9-11 respectively illustrate the nature of two modified turbulence type amplifiers each of which has just one of the above mentioned general characteristics. Referring to FIGS. 7 and 8 there is illustrated a turbulence type amplifier having means defining a fluid entrainment chamber 116, a fluid supply conduit 112, 113, a control means 13S and an emitter orifice 120 which respectively correspond in construction and operation to that described above for elements 16, 12, 13, 35 and 20 of the amplifier of FIGS. 1-3. The amplifier in FIGS. 7 and 8 is provided with any suitable type of collector which for example may include a collector tube 126 which has a bore 127 formed therethrough that has an operative inner end 130 positioned in axially alignment with the emitter orifice 120. The outer end of collector tube 126 communicates with a means 131 to be operated under the control of the amplifier. The collector tu-be 126 is secured by any suitable means in a collar 124 that is fixedly mounted by any suita-ble means on the downstream end of the main body member 110; said downstream end of the body member 110 being formed with a suitable axial type recesss 117 and suitable radial type vent holes 121 and 122.

The inverse output characteristic of operation of the amplifier illustrated in FIGS. 7 and 8 corresponds to that described above for the amplifier of FIGS. 1-3. Thus in the normal state when no signal fluid flow 13S exists the fluid flow from the emitter orifice will be turbulent and hence the fluid pressure in the collector tube 126 will Abe relatively low. Conversely when a signal fluid flow 138 is applied the stream of fluid issuing from the emitter orifice 120 will become laminar as above described and hence the fluid pressure in collector tube 126 will be significantly increased. Thus each of the induction type turbulence amplifiers of FIGS. 1-3 and FIGS. 7-8 will have an operational output which is inverse from that of conventional turbulence type amplifiers.

Referring to FIGS. 9-11 another turbulence amplifier is illustrated which utilizes a more or less conventional type emitter in combination with a flared diffuser surface such as is used in the apparatus of FIGS. 1-3. Here the turbulence amplifier comprises a main body member 210 that is formed with an elongated axial bore in which is secured an emitter tube 212 that has a smooth axial bore 213 formed therethrough. The outer end of bore 213 is connected by any suitable means to a fluid pressure source 214 while the inner end of the said bore 213 communicates directly with an emitter orifice 220' that defines the inner reduced end of a funnel-like recess 217 formed in the downstream end of the main body 210', the funnel-like recess being defined by the flared diffuser surface 21S. Secured by any suitable means to the downstream end of said main body 210 is a collar 224. Fixedly mounted in a suitable bore formed in collar 224 is a collector tube 226 having a bore 227 formed therethrough. The inner end of tube 226 is disposed in the chamber 217 and is in axial alignment with the emitter orifice 220 while the outer end thereof is connected by any suitable means to a device 231 to be controlled. The said downstream end of the main body member 210 is also formed with suitable radial vent holes 221 and 222. Surrounding a portion of the inner end of the collector tube 226 is an annular member 253 which is comprised of a cellular or sponge-like material having minute open pores. This annular poroused member is constructed and arranged so that substantially all the fluid exhausting through the vent holes 221, 222 must pass through the cellular material. The porous member 253 thus absorbs the redirected internally generated sound waves in a manner corresponding to that described above for said porous member S3 of' FIG. l, and further isolates the fluid flow in the tapered recess 217 from any sound waves originating from external sources.

A control means is provided for the turbulence amplifier of FIGS. 9-11, such control means comprising a radial type bore 232 formed in the wall of the main body member 210. The inner end of bore 232 communicates with the tapered recess 217 at a point just downstream from the emitter orifice 220 while the outer end of bore 232 communicates with an axial bore 233 formed through a tubular fitting 234 that is secured by any suitable means in said main body member 210. Any suitable signal generating means may be used to initiate control pulses or other signals in the bores 233 and 232.

`In the operation of the turbulence type amplifier of FIGS. 941 a laminar stream of fluid normally issues from emitter orifice 22() and this stream is directed into the collector bore 227 so that the fluid pressure level in said bore 227 is normally relatively high. When an appropriate pressure impulse or other control signal is introduced into the bores 233 and 232 the fluid flow in chamber `217 becomes turbulent in accordance with known phenomena and this turbulent fluid stream then tends to attach itself to or at least follow along the diffuser surface 218 so as to pass through the open pores of the annular member 253 and out through the vent holes 221, 222 into the surrounding atmosphere. Under these turbulent flow conditions a relatively low fluid pressure will exist in the collector bore 227. When the control signal is terminated the fluid flow issuing from emitter orifice 220 will automatically revert to its initial laminar condition and the fluid pressure in the collector bore 227 will then increase to its normal relatively high level. As was indicated above in connection with FIGS. 1-3vthe provision of a flared diffuser surface adjacent to the discharge side of the emitter orice greatly improves the stability of operation of the ampliiier in both operational modes by minimizing sonic and shock load interferences with the lluid ow in the ampliiier. Further here the porous annular-member 253, FIG. 9, will tend to absorb not only the redirected internally generated sound waves but any sound waves originating -from external sources.

Amplifiers of the type illustrated in FIGS. 9-11 have been found to be very inexpensive to produce and most reliable in operation. The recess 217 may be bell shaped or even conical. Said recess 217 may also be shaped so as to have a rectangular cross sectional shape and be divergent only in a single plane e.g. in the plane of FIG. 9.

Referring to FIGS. l2-15 a specic structural embodiment for a novel wall and jet interaction device is shown. The operation of this particular uidic device is dependent upon three functional characteristics, namely a Wall interaction efect, a jet deflection, and an operative combination of laminar and turbulent fluid ilow conditions. Referring specically to FIGS. 12 and 13 the iluidic device shown comprises a composite body unit 300 which includes a lower main plate 301 and a superimposed cover plate 302 that is sealingly secured by any suitable means to the grooved upper face 303 of said lower main plate 301. The cover plate 302 has been omitted from FIGURE 12 for the sake of clarity. The various grooves formed in plate 301 effectively define a plurality of fluid conducting passages for the instant uidic device and comprise an emitter groove 3-10 that communicates at one end with a uid pressure input or supply aperture 311 While the other end thereof communicates with the upstream end of an interaction chamber groove 312, groove 312 being formed slightly deeper (as seen in FIG. 13) than said groove 310. A collector groove 313 communicates between the other end of said interaction chamber groove 312 and an output aperture 314. As may be seen from FIGURES 12 and 13 the longitudinal axes of the emitter, collector and chamber grooves 310, 313A and 312 are disposed in the common vertical section plane of FIG- URE 13 and the chamber groove 312 is substantially symmetrical with respect to its longitudinal axis. The downstream end of the chamber groove 312 is formed with two lateral extensions 315 and 316 which respectively communicate with two venting apertures 317 and 320. The two side walls 322 and 323 of the interaction chamber groove 312 are formed with four control ports 324, 32'5, 326 and 327 which form the respective ends of four small signal control line grooves 330, 331, 332 and 333, respectively. Grooves 330, 331, 332 and 333 communicate with conduit line grooves 334, 335, 336 and 337, respectively which in turn communicate with four signal control apertures 340, 341, 342 and 343 respectively. Extending through and secured to the main plate 301 are a plurality of tubular inserts or fittings, such as 355, the passages therein effectively defining the said apertures 3-11, 314, 340, 341, 342 and 343 respectively, these iittings providing a means for operationally coupling the various amplifier grooves to external tubing or other fluid conduits forming part of the iluid circuit in which the instant fluidic device may be incorporated. For the purposes of illustration all of the tubular inserts 355 respectively associated with apertures 311, 314, 340, 341, 342 and 343 have been shown in FIGURE 13. The venting apertures 317 and 320 formed through plate 301 communicate directly with the surrounding medium as illustrated in FIGURE l5.

All of the grooves formed in the lower plate 301 have substantially rectangular cross sectional proles. The plan view coniigurations for the various grooves are shown to actual scale in FIG. 12. The length of the emitter groove 310 should be 35 to 85 times the longest width or depth dimension of the cross sectional profile of said emitter groove. The depth of the interaction chamber groove 312 should be between 1 and 4 times the depth of the emitter groove 31.0, while the width of said chamber groove 312 should be less than 10 times the width of the emitter groove 310. The aspect ratio of the depth and width dimensions of the cross sectional profile of the emitter groove should be between l to 1 and 2 to 1, a square proiile here being very desirable. The distance between the emitter and collector, i.e. between points 34S and 346 should be between 15 and 40 times the length of the shortest width or depth dimension of the cross sectional profile of said emitter groove 310. One uid device, which has been constructed was dimensioned so as to have an emitter groove width W, as seen in FIGURE 12, of .016, control port widths of .006, a collector groove width of .016", an interaction chamber width of .100; and an emitter groove depth D, as seen in FIG. 13, of .015, control port depths of .008, an interaction chamber groove depth of .040" and a collector groove depth of .015 all depth dimensions being measured from a common plane dened by the upper planar Surface 303 of the main plate 301. The operational supply pressure used here was approximately 1 pound per square inch. It will be understood that these specie dimensions for said fluid device are listed for the purposes of illustration only and that various other corresponding dimensional sizes may be used for the instant type of uidic device.

The operation of the uidic device illustrated in FIG- URES 12-15 will now be described. Fluid under pressure from a suitable pressure source not shown is caused to flow into the supply aperture 311 and to flow through the emitter groove 310 so as to form a laminar jet 344 that normally issues from the downstream end 345 of said emitter groove 310. The laminar jet 344 is directed into the open end 346 of the axially aligned collector groove 313 and hence fluid may ow through said groove 313 and said output aperture 314 to a device to be controlled or operated. Any simultaneous iluid ow in the interaction chamber groove 312 that does not ilow into the collector groove 313 may leave the the system via the venting apertures 317 and 320. In this rst or normal operative mode or condition of the uidic device the uid recovery pressure in the collector groove 313 will be relatively high. When it is desired to change the operative condition of the device a iluid pressure control signal is introduced through any one of the four control line grooves 330, 331, 332 or 333. When an appropriate uid pressure control signal is introduced through the control line groove 332, for example, and against the side of the said laminar jet 344, three significant changes occur. First the laminar jet issuing from the emitter groove becomes turbulent, secondly, the jet of fluid issuing from said emitter groove is caused to deflect to a substantial extent towards said side wall 322, the axis of this turbulent uid flow in this case being deflected to the left, i.e. towards said side wall 322, asseen in FIG. 12, and thirdly the thus deected turbulent iluid stream eifectively interacts with the said side wall 322, and to some extent with the other side wall 323 of the interaction chamber groove 312, in owing towards the venting apertures 317 and 320 at the downstream end of said chamber groove 312. The arrows 347 and 350 indicate only the general nature or limits of the principal deflected turbulent flow stream moving towards vents 317, 320 and of course do not define the various local eddies and the back ow that may exist in the interaction chamber. It will be noted in this operational example that the main turbulent stream initially effectively interacts with the side wall 322 at a region farther upstream, or nearer the emitter end 345, than the region at which said stream interacts with the opposite side wall 323. This is to be expected in view of the above mentioned leftward detiection of the axis of the main fluid stream. As will be apparent most of the fluid flow during this deflected turbulent mode or condition of operation of the instant device will exit through the venting holes 317 and 320 and only a relatively small amount thereof will enter the collector groove 313. Thus in this second operative mode or condition the liuid recovery pressure in the collector groove 313 will be relatively low. When the uid control signal applied through control line groove 332 is terminated the uid flow in said interaction chamber groove 312 will immediately return to its said iirst or normal operative condition. If the control signal has been applied through either of the control line grooves 330 or 331 on the other side of said interaction chamber groove 312 the said laminar jet 344 would have been correspondingly deliected generally to the right or toward wall 323, as seen in FIG. l2 and the main uid stream would have initiated interaction with the wall 323 in a region that is farther upstream, or nearer to emitter end 345, than the region where said main stream would have initiated interaction with the wall 322; the fluid exhaust flow here again taking place through the venting apertures 317 and 320 and the fluid recovery pressure in the collector groove 313 again being relatively low. The presence and the relative positions of the top and bottom wall surfaces, as seen in FIGS. 13 and 14, of the interaction chamber with respect to the emitter groove 310 assist in establishing the above described iiuid ow patterns.

The above discussed three operational characteristics of the instant device, i.e. the shift from laminar to turbulent iluid flow conditions, the deflection of the main luid stream, and the wall interaction effects, resulting when the instant device is shifted from its said first to its said second mode of operation are produced by the combined effects of the geometry of the uid conducting passages in the device dening the emitter and collector, and the provision of the substantially enclosed region between said emitter and the collector so as to provide the said liuid flow interaction walls or surfaces. With this type of arrangement two very significant advantages are obtained. First the eiective distance between the emitter and co1- lector of the instant device, that is the distance between the emitter and collector ends 345 and 346 respectively, may be greatly shortened which in turn makes possible higher switching speeds and higher normal recovery pressures in the collector. In addition this shortened emitter to collector distance will increase the operational stability of the unit and will decrease its sensitivity to sound waves and environmental vibrational and/or shock conditions. Secondly, the provision of the said enclosure and the charnber walls makes possible the use of very low power control signals which in turn allows for greater fan out in fluid control circuits that include the instant type of iluidic devices.

The above mentioned reduction in the power requirements for the control signals is made possible, at least in part, by the generation of low fluid pressures in those two offset or laterally disposed upstream corner regions of the instant interaction chamber, one of said regions being located adjacent the control ports 324 and 325 while the other of said regions is located adjacent said control ports 326 and 327. Here when a control signal is introduced into the interaction chamber, as above described, the initial slight deflection of the main liuid stream and the lateral spreading effect of the initial turbulent flow in said main stream causes said main stream to interact with the chamber walls as above described so that said low pressure regions apparently become effectively isolated from the downstream portions of the interaction chamber. Under these conditions the aerodynamic effects 0f said deilected and laterally spread main stream will start the generation of a reduced fluid pressure in said regions and once started, even by a relatively weak control signal, power from the main fluid stream tends to build up and maintain the relatively low fluid pressures in said regions. Thus a control signal applied to the instant device need only be of a magnitude suicient to initiate this control action, a large portion of the actual control power thereafter required being derived from the main Huid stream itself.

As will be apparent the two above discussed operational advantages of the instant invention, i.e., relatively high pressure recovery and relatively low power requirement for control signals, will permit such a fluidic device to be incorporated in a fluid logic or control circuit so as to efficiently control a relatively large number of other similar fluidic devices.

The wall and jet interaction type of device illustrated in FIGS. 12-15 may be constructed to operate over a relatively wide range of supply pressures namely from less than l pound per square inch up to approximately 10 pounds per square inch, and for any one given device a supply pressure variance ratio of up to 2 to l is tolerable. The particular construction and arrangement shown in FIGS. 12-15 gives rise to a marked improvement in the operational stability of this general type of uidic device and the solid rugged nature of the instant construction allows the device to be used in installations where adverse environmental conditions exist. Further the instant venting arrangement minimizes operational interference by sonic waves from external sources.

An alternate arrangement for the plan view configuration of the grooved lower plate is shown in FIG. 16. Here the shape of the interaction chamber groove 312a is charged so the side walls thereof symmetrically diverge at an angle A from a point just downstream from the control ports 324g and 327a, the angle A having a typical value less than 35 degrees and an illustrated value of between 25 and 30 degrees. Here the reference numerals and dimensions of the various grooves and the general characteristics of operation otherwise correspond to those respectively described in connection with FIGS. 12-15. The above mentioned low uid pressure regions in the interaction chamber groove 312a are indicated by reference numerals 353a and 354:1 respectively.

Referring to FIGS. 17-21 a laminated construction is illustrated for a bistable liuidic unit `410. Unit 410 comprises a lower grooved plate 411 and an upper cover plate 412 which is sealably secured by any suitable means to said lower plate so as to thereby establish the fluid flow passage network to be described below. The conigurations of the fluid flow passages are largely determined 'by the nature of the grooves and chambers formed in the upper face of said lower plate 411 and particular reference to FIGS. 17 and 21 will be made in connection with a detailed description of the shape and extent of said passage. The instant device includes an emitter which is essentially delined by a straight elongated groove or supply line 413 which has an upstream end that cornmunicates with a supply chamber `414 and a downstream end that communicates with an interaction chamber 415. Chamber 41,5 is substantially symmetrically arranged with respect to the longitudinal axis 416 of the emitter groove 413 except for a right side guide wall 417 as seen in FIG. 17 which is formed at an angle B, FIG. 2l of between 5 and 20 degrees with respect to said axis 416. The dotted line 417g, FIG. 17, indicates where the side Wall 417 would be if said interaction chamber were completely symmetrically shaped and arranged with respect to said axis 416. The upstream end of side wall 417 is set back a distance S, FIG. 21, from the adjacent side edge 418 of the emitter outlet opening 419. The downstream end of interaction chamber 415 is formed with two arcuate concave end walls 420 and 421 which terminate at projections 422 and 423 that extend slightly upstream in the chamber 415 as illustrated in FIG. 17 and define a collector orifice or opening 424 for the instant uid amplilier. The collector of the unit 410 is essentially defined by an elongated straight groove 425 or output line which is coaxially disposed with respect to the emittter groove 413. The upstream end of the collector groove 42S communicates with the interaction chamber while the downstream end thereof communicates with an output chamber 426. A iirst control line or groove 430 is formed in the lower plate 411, one end 13 thereof communicating with a downstream portion of the interaction chamber 415 through side wall 417, while the other end thereof communicates with a signal chamber 431; the axis of control groove 430 being substantially normal to the axis of said emitter groove 413. A second control line or groove 432 is formed in plate 411 and has one end thereof communicating with an upstream portion of the interaction chamber through the opposite side wall 434, FIG. 20, of the chamber 415 while the other end thereof communicates with a signal chamber 433, the axis of groove 432 being substantially normal to the axis of said emitter groove 413.

The lower plate 411, which is grooved as above described, is sealingly covered by the plate 412 as illustrated in FIGS. 19 and 20. This cover plate is formed with a plurality of suitable bores which are respectively adapted to receive a plurality of tubular fittings 440- 445, the latter being respectively secured in said bores by any suitable means such as soldering, brazing, etc., as is illustrated at 446 of FIG. 20. The tubular fittings 440, 441, 442, 443, 444, `445 are located in the cover plate at the positions shown in FIG. 18 and respectively communicate with the various grooves and chambers in the amplifier unit at points denoted by the dotted line circles 440:1, 441:1, 44201, 443a, 44411 and 44Sa, respectively, of FIG. 17. The fitting 440 is adapted to be pneumatically coupled to a fluid pressure source and the fitting 445 is adapted to be pneumatically coupled to the device to be controlled. Fittings 443 and 444 are provided for venting purposes and operatively communicate with the respective side portions of the downstream end of the interaction chamber 415 while the two fittings 441 and 442 are respectively pneumatically connected to the means for generating the pneumatic input signals which are to control the operation of the instant bistable turbulence type amplifier. The shape of the groove and channel arrangement is shown to actual scale in FIG. 17; the groove width W having an exemplary value of .O-.020 inch.

In the operation of the instant bistable device air or other suitable fluid from a suitable pressure source flows through fitting 440, chamber 414, emitter groove 413 and into the interaction chamber 415. The elongated nature of emitter groove 413 causes a laminar type air jet to issue from the downstream end 419 of the emitter and to flow down the length of said chamber 415 and into the upstream end 424 of the collector groove 425. The impact recovery pressure existing in the collector groove 425 because of the receiving of this laminar air jet from the emitter causes the pressure in the output chamber 426 to remain at a relatively high level. The Iinstant amplifier will remain in this first stable operating condition until caused to shift to a second stable operating condition by the application 0f suitable control input pressure signals as will now be described. When a pressure input signal is initiated in the control groove 432 the laminar flow in the jet of air issuing from the emitter is disrupted and becomes turbulent whereupon the impact recovery pressure in the collector drops appreciably. This turbulent flow condition will continue to exist even after termination of the said input signal and the instant amplifier will remain in this second stable condition until caused to return to said first condition by an appropriate further control signal. In either stable operative condition much of the air flow is exhausted through the venting fittings 443, 444. At such time as it is desired t-o have the amplifier return to its first mentioned stable condition, a restoring control pressure signal is initiated in the control groove 430 and such will cause the fluid jet to assume its original laminar flow state which will persist, as before, even after termination of the said restoring control pressure signal, so that the impact recovery pressure in the collector increases to said relatively high level. In conventional type amplifiers as opposed to the instant device the turbulent fluid flow state continues only as long as a control signal is applied.

The technical explanation of why the turbulent flow conditions in the instant amplifier persist after termination of the control signal initially producing the turbulent flow is not entirely clear. Apparently the initiation of a fluid pressure signal in the control groove 432 deflects the fluid jet leaving the emitter towards the side wall 41'7 so as the resultant turbulent fluid flow attaches itself to and/or follows along the length of said wall 417 and upon encountering the end wall 420 and projection 422 generates sonic feed back waves. At least a portion of -these sonic waves travel back upstream through the interaction chamber 415 and cause the laminar fluid flow leaving the emitter orifice 419 to become turbulent. Thus once this feed back of sonic energy is initiated by the signal deflection of the fluid stream issuing from the emitter the feed back action ris self-sustaining in that a portion of the energy of said fluid stream is fed back and used to retain this fluid flow in the turbulent deflected state. When the operational mode of the amplifier is to be returned to the first or laminar flow condition apparently the initiation of a pressure signal in the control groove 430 momentarily interrupts the fluid flow which generates said sonic feed back waves and in that control groove 430 is rather far away from emitter orifice 419 the emitter jet is no longer disrupted either by said signal from control groove 430 0r the said feed back action and thus returns to and remains in a laminar condition in flowing through the interaction chamber 415. The above explanation of just why the device has a stable turbulent mode of operation is somewhat conjectural.

A bistable turbulent amplifier has been constructed 'in accordance with the above description and has been found to operate reliably over extended periods of use. The bistable amplifier, which is illustrated to scale in FIG. 17, has an emitter throat width W' of .O15 inch and all the said grooves and chambers have substantially rectangular cross sectional shapes; the depth of grooves 413 and 425 and chamber 415 being approximately .015 inch. The set back distance S, FIG. 20, is preferably between .005 and .050 inch. It will be understood that these dimensions are listed here for illustrative purposes and that various other ranges and combinations of dimensions may be used.

What is claimed is:

1. A turbulence type amplifier: comprising an emitter adapted to be coupled to a fluid supply source and operative to issue a jet of fluid;

a collector operatively arranged in the flow path of said jet of fluid issuing from said emitter;

Said emitter having a conduit means therethrough, the

latter including a control chamber whichis vented to a secondary fluid source and across which chamber the supply fluid must flow before issuing from said emitter whereby a laminar flow of supply fluid in passing through said chamber may entrain fluid from said secondary source and thereby cause a turbulent flow condition to exist in said jet of fluid issuing from said emitter; and

control means coupled to said emitter for restricting the amount of fluid flow from said secondary fluid source to said control chamber whereby the laminar flow of said supply fluid may persist in said jet of fluid issuing from said emitter upon the application of a control signal to said control means.

'2. In a turbulence type amplifier having an emitter adapted to be coupled to a source of supply fluid and having a main fluid conducting channel formed therethrough, said channel having an upstream portion for producing an initial laminar flow in the supply fluid moving therethrough and having a discharge end through which a jet of fluid may issue; and

a collector operatively arranged so as to receive at least a portion of the jet of fluid issuing from said emitter; the improvement comprising signal control conduit means operatively communicating with said main fluid conducting channel at a point upstream from the said discharge end of said channel, said signal conduit means when effectively open to a secondary fluid source serving to conduct additional fluid from said secondary 'source to said channel so that said additional fluid is entrained in the flow `of said supply fluid through said channel a collector operatively arranged in the path of flow of said jet of fluid;

control means adapted to apply control signals to the amplifier so as to control the laminar and turbulent flow conditions in said jet of fluid;

means defining a wall surface that extends adjacent the region between said emitter and said collector and to which at least a portion of said jet of fluid may attach itself when said jet of fluid is in said turbulent flow condition and l thereby causing turbulence in said jet of fluid issuing sound Wave absorbing means operatively disposed in from said emitter, said signal conduit means when at said amplifier to receive and at least partially absorb least partially blocked thereby reducing the amount sound Waves moving through said amplifier. of said additional fluid flow possible from said sec- 8. Apparatus as defined by claim 7 wherein said sound ondary source to said main channel and allowing Wave absorbing means includes a cellular material that said laminar flow condition existent in said upstream portion of said channel to persist in the jet of fluid issuing from said emitter.

3. Apparatus as defined by claim 2: additionally comconditions in said chamber and in the fluid flow issuing from the discharge end of said emitter; and a collector disposed in operative relation to said emitter and adapted to intercept at least a` portion of the fluid flow from said emitter whereby when said control conduit means is at least partially blocked a laminar flow condition will exist in the fluid issuing from the discharge end of the emitter so that an increase in pressure is thereby produced in said is operatively disposed along the fluid vent path of the amplifier.

9. In a turbulence type amplifier having an emitter adapted to be coupled to a fluid supply and prising operative to normally issue a laminar jet of fluid;

means for inhibiting the flow of fluid through said a collector operatively arranged in the path of flow conduit means. of said jet of uid; and

4. A turbulence type amplifier: comprising signal control means for controlling shifts to and from an emitter having a main fluid conducting channel the laminar and turbulent operational modes of the formed therein, the discharge end of said emitter amplifier; channel having an opening through Which fluid may the improvement comprising exhaust while the other end of said channel is adapted means coupled to said amplifier and having formed to be coupled to a source of supply fluid so as to thereon a three dimensionally flared diffuser surface thereby make possible a normal laminar flow 0f that extends divergently in the region between the supply fluid from the discharge end of said channel, discharge end of said emitter and the upstream end said main channel including an enlarged fluid enof said collector, the reduced upstream end of said trainment Vchamber which is located just upstream flared diffuser surface being disposed adjacent the from said discharge end of said channel; downstream end of said emitter so that a turbulent fluid control conduit means communicating with said stream of fluid from said emitter may attach itself enlarged chamber for establishing turbulent flow to said surface in progressively moving radially outward in a substantially closed front away from the axis of said emitter.

10. Apparatus as defined by claim 9 wherein said flared diffuser surface extends in a downstream direction to an extent so as to be effectively downstream from the effective upstream end of said collector.

11. A turbulence type amplifier: comprising an emitter adapted to be coupled to a source of fluid supply and operative to issue a jet of fluid, said jet collector, and conversely when an increase in the normally being laminar; flow through said conduit means into said entraina collector operatively arranged in the flow path of ment chamber is permitted a resultant turbulent flow said jet of fluid issuing from said emitter; said emitter condition will exist in the fluid issuing from the and collector being arranged so that at least a portion discharge end of the emitter so that a decrease in of a turbulent jet of fluid from the emitter will fluid pressure is thereby obtained in said collector. follow a venting path away from said collector; 5. A turbulence type amplifier: comprising signal control means operatively coupled with said an emitter adapted to be coupled to a source of supply emitter and collector so as to control the turbulent fluid having a main fluid conducting channel formed and laminar flow conditions in said jet of fluid; therethrough and terminating at an outlet orice and from which a jet of fluid may issue; sound wave absorbing means operatively positioned a collector operatively arranged in the path of flow of said jet of fluid issuing from said emitter; and

a fluid signal conduit means coupled with said emitter so as to communicate with said main fluid conducting channel of said emitter at a point upstream from said outlet orifice so that the jet of fluid issuing from said emitter outlet orice is normally turbulent and is made laminar when a signal is applied to said signal conduit means.

6. Apparatus as defined by claim 5 wherein the downalong said venting path.

12. Apparatus as defined by claim 11 wherein said sound wave absorbing means includes a porous material.

13. Apparatus as defined by claim 11 wherein substantially all of the fluid venting from said amplifier passes through said porous material.

14. Apparatus as defined by claim 11 additionally comprising sound waves deflecting means having a divergent diffuser surface formed thereon, the upstream end of said surface being operatively disposed adjacent the discharge stream end of said emitter is formed with a flared diffuser recess and wherein said collector is disposed so that its upstream end is located in said recess whereby a turbulent flow of fluid from said emitter will tend to aerodynamically attach itself to the surface of said flared diffuser recess and thereby increase the stability of the turbulent operational mode of the amplifier.

7. A turbulence type amplifier: comprising an emitter adapted to be coupled to a fluid supply and operative to issue a jet of fluid;

end of said emitter.

15. In a turbulence type amplifier:

an emitter adapted to issue a jet of fluid;

a collector operatively disposed so as to receive at least a portion of said jet of fluid;

venting means for said amplifier;

means defining a fluid flow guide wall, said wall extending generally adjacent to the region between said Collector and emitter, the operative upstream portion 17 of said wall being disposed laterally adjacent the downstream end of said emitter; l a first control means arranged so as to be in operative relation with respect to said jet of fluid flowing between said emitter and collector and operable when said main body also having a second control line formed therein which communicates with an opposed side of said chamber whereby when the fluid flow in said jet becomes turbulent it interacts with both of said side walls simultaneously.

a control signal is applied therethrough to disrupt 19. A bistable turbulence amplifier: comprising a laminar flow condition in said fluid jet so that a an emitter adapted to be coupled to a fluid pressure turbulent fluid flow exists in said region, said turbusource and to issue a jet of fluid;

lent fluid flow effectively attaching itself to said fiuid a collector operatively arranged to receive at least a guide wall and persisting in said attached state after lo portion of said jet of fluid;

termination of said control signal; and venting means for said amplifier;

a second control means arranged so as to be operative means defining a guide surface that extends adjacent on said jet of fluid between said emitter and colthe region between said emitter and said collector, lector and operable when a control signal is apsaid surface being shaped so that a portion of said plied therethrough to effectively terminate the atjet 0f fluid may be redirected S0 as i0 maintain a turtached turbulent fluid flow along said guide wall and bulent fluid flow in said jet of fluid as the latter atpermit a laminar fluid flow to again exist between taches itself to and follows along said guide surface, said emitter and said collector. at least a portion of said guide surface being disposed 16. A turbulence type amplifier: comprising at an angle of less than 20 degrees from the longitudia main body; 2() nal axis of the discharge end of said emitter whereby an emitter operatively arranged in said main body s0 as a turbulent fluid ffOW along said surface Will tend t0 to be capable of issuing a laminer jet of fluid; remain attached to said surface after termination of a collector operatively arranged in said main body so the associated control signal; and

as to receive at least a portion of the fluid jet issuing Signal control means for causing said jet of uid to be from Said emitter; deflected towards and away from said guide surface.

said main body in the region between said emitter and 20- In aturbulence type amplifier:

collector being formed with walls that define an ina rnain body including teraction chamber across which said jet of fluid an emitter adapted to be Coupled to 'f1 sourCe of tluid passes in moving between said emitter and collector; Supply and t0 issue a jet of fluid;

Venting means for Said chamber; a COlleCOl operatively aligned With Said emitter and one side wall of said interaction chamber having an hai/ing an upstream end that is adapted to reCeiVe at upstream turbulent fluid flow attachment portion least a Portion of said let of fluid Whereby When the which is disposed adjacent to the discharge end of operatiVe lloW Conditions in said let of fluid are Said emitter; changed between the laminar and turbulent states the a rst Control lino formed in Said mail] body and comfluid pressure in said collector will be correspondmunicating with said chamber and operative when a ingly Changed;

Signa] is applied therethrough t() disrupt a laminar a I'S COl'lllIOl 11163115 fOI' altering the flOW lll Said jet flow condition in said fluid jet and initiate a stable from alelninar to turbulent state;

turbulent fluid flow in said fluid jet that persists after lloW retaining ineens for holding the turbulent fluid the termination of Said signal; and 40 flow in a turbulent state after the termination of a a second control line formed in said main body and signal frorn seid iirst fluid Control Ineens; and

communicating with Said interaction Chamber and a second control means for terminating the effective opoperative when a signal is applied therethrough to eferation of said retaining ineens whereby the iloW Confectively terminate said turbulent flow and again perditions in seid Fluid let may return t0 a laminar State. mit a laminar flow to exist in said jet of fluid between 21- Apparatus as denned by Cleini 20 wherein Said flow said emitter and oollootorl retaining means includes a guide surface having an up- 17. Apparatus as defined by claim 16 wherein said first Stream end that is operatively disposed adjacent t0 the and second control lines respectively communicate with downstream end of Said emitter and along Wliiell at least said interaction chamber through opposite side walls of abortion of saidlet niay fOlloW- said interaction Chambon 22. Apparatus as defined by claim 20 wherein said lg Aturbulonoe typo amplifier: comprising second control means includes a fluid control passage a main body; that effectively terminates adjacent said guide surface.

said main body having an elongated supply line formed 23- Apparatus as delined by Claim 202 additionally therein, said supply line being adapted to be coupled Comprising to a source of fluid pressure and to normally issue a 5r means defining an interaction chamber in the region laminar jot of fluid from the downstream end thero d between said emitter and collector, said chamber of; being partially defined by said guide surface and an said main body having an interaction chamber formed ,Opposing Side Well surfaCe;

therein, said chamber communicating with the down- Said first Control n ieans including a fluid COIltrOl P21S- stream ood of said supply lino; sage that effectively terminates adjacent said opsaid main body having a fluid receiving operative output posing Side Wall Surfaceline formed therein, the upstream end of said output 24- APlo'eretus 3S defined by claim 23 wherein the Plnn lino communicating with said interaction chamber; configuratlon of said interaction chamber is asymmetrisaid main body boing provided with Venting means cal about a central longitudinal axis passing through the that communicates with said interaction chamber operative downstream end 0f Said emitter.

whereby when the fluid flow in said jet becomes turbulent it fills the downstream end of said interaction chamber and exhausts through said venting means to the surrounding medium;

the walls defining said chamber including opposed fluid flow interaction side walls that extend from a point adjacent the downstream end of said supply line;

said main body having a first control line formed therein which communicates with one side of said interaction chamber; and 75 25. A bistable turbulence amplifier: comprising an emitter adapted to issue a jet of fluid, said jet being capable of alternately assuming laminar and turbulent flow states;

a collector operatively arranged to receive at least a portion of said jet of fluid whereby when the flow condition in said fluid jet ischanged between the laminar and turbulent states the fluid pressure in said collector will be correspondingly changed;

venting means for said amplifier;

means delining a iiuid iiow attachment wall that extends from a point adjacent the downstream end of said emitter to a region adjacent one side of the upstream end of said collector and to which a jet of fluid from said emitter may attach;

feed back means for feeding back a portion of the energy in said jet of fluid to an upstream portion of said jet of fluid so that said jet once changed to the turbulent state and attached to said wall can thereby retain itself in said turbulent attached state without the aid of externally applied signals; and

signal control means for causing said jet of fluid to be shifted between the turbulent and laminar flow states.

26. Apparatus as delined by claim 25 wherein said feed back means includes a means to redirect a portion of said attached jet of iiuid back towards an upstream region thereof.

27. Apparatus as defined by claim 25 wherein said feed back means includes a means for directing sonic waves towards an upstream region of said jet of liuid.

28. Apparatus as defined by claim 25 wherein said signal control means includes means defining two separate control lines each of which is capable of effectively changing the iiow conditions in said jet of fluid from one of said states to the other of said states.

29. A turbulence type amplifier: comprising a main body;

said main body defining an emitter adapted to issue a jet fluid, said jet being capable of alternately assuming laminar and turbulent flow states;

a collector operatively arranged to receive at least a portion of said jet of fluid whereby when the iiow condition in said jet of liuid is changed between the laminar and turbulent flow states the iiuid pressure in said collector is correspondingly changed;

venting means for said amplifier, said venting means being always open to the surrounding medium;

said main body being formed with a fluid iiow attachment side wall surface which extends from a point adjacent the downstream end of said emitter to a region adjacent one side of the upstream end of said collector and to which a jet of fluid in the turbulent iiow state may attach;

the upstream end of said side wall being laterally set back from the side of said jet of iiuid by a distance of between .005 and .050 inch, said side wall also extending at an angle of less than and 20 degrees with respect to the axis of said emitter;

means disposed in said interaction chamber for generating sonic feed back waves in response to the ow of liuid along said wall so as to cause said uid flow to continue being attached to said side wall surface after the termination of a signal that initiated said flow along said surface; and

signal control means for causing said jet of fluid to be shifted between turbulent and laminar flow states.

30. A turbulence type fluidic device: comprising an emitter adapted to issue a jet of fluid;

a collector aligned with said emitter and adapted to receive at least a portion of said jet of fluid;

means defining a substantially closed interaction chamber that includes the region between said emitter and collector;

said emitter, collector and interaction chamber being arranged so that said jet of iluid is normally in a laminar iiow condition and is cross sectionally well defined throughout its operative length between said emitter and collector, said jet of fluid when in its turbulent ow condition being diffused and spread across substantially the entire cross section of the downstream end of said interaction chamber;

venting means for venting iiuid flow to the surrounding medium simultaneously from both` lateral down- 20 stream sides of said interaction chamber when the flow condition of said jet of fluid is turbulent; and

a plurality of selectively operable fluid jet control means for controlling the shifting of said jet between its said laminar and turbulent flow conditions.

31. Apparatus as defined by claim 30 wherein the upstream end of said interaction chamber includes at least one low pressure region that is laterally offset from the downstream end of said emitter whereby a reduced static pressure is generated in said low pressure region when said jet of fluid is in said turbulent diffused flow condition.

32. Apparatus as defined by claim 30 wherein the effective width of said interaction chamber is substantially greater than the corresponding effective width of said emitter, and the elecive depth of said interaction chamber is substantially greater than the corresponding effective depth of said emitter.

33. Apparatus as defined by claim 30 wherein the effective upper portions of the walls of said emitter and interaction chamber respectively, are substantially coextensive.

34. Apparatus as defined by claim 33 wherein said interaction chamber is laterally substantially symmetrically arranged with respect to said venting means and to the axis of said emitter and collector.

35. A fluidic device; comprising an emitter adapted to issue a stream of liuid;

a collector aligned with said emitter and adapted to receive at least a portion of said stream of fluid issuing from said emitter, said emitter and collector being arranged so that an operative combination of alternate laminar and turbulent fluid flow conditions may exist in said iiuid stream;

means delining a substantially closed interaction chamber that includes the region between said emitter and collector, said interaction chamber being partially defined lby two laterally offset side walls that are disposed on opposite sides of said region so that when said turbulent fluid flow condition exists in said region the turbulent fluid iiow will simultaneously interact with both of said laterally offset side walls;

said interaction chamber being further partially defined by another wall that extends substantially parallel to the axis of said emitter and along -which fluid from said emitter may ow when either a laminar or a turbulent fluid flow condition exists in said region;

venting means communicating with the downstream end of said interaction chamber for simultaneously venting turbulent iiuid flow from fboth sides of said downstream end of said interaction chamber; and

control means for controlling the switching of said fluid ow between the said laminar and turbulent iiow conditions.

36. Apparatus as defined by claim 35 wherein the effective width of the upstream end of said interaction chamber is between 2 and l0 times the corresponding width of the downstream end of said emitter.

37. Apparatus as defined by claim 35 wherein said interaction chamber has a plan profile that is substantially symmetrically shaped and positioned with respect to the axis of said emitter.

38. Apparatus as defined lby claim 35 wherein the effective upper portions of the walls of said emitter and interaction chamber respectively, are substantially coextensive.

39. Apparatus as delined lby claim 35 wherein the depth of said interaction chamber is greater than one but less than four times the ydepth of said emitter.

40. A fluidic device: comprising an emitter adapted to issue a stream of fluid;

a collector aligned with said emitter and adapted to receive at least a portion of the stream of fluid issuing from said emitter;

said emitter and collector being arranged so that an operative combination of alternate laminar and turbulent Huid flow conditions may exist in the region between said emitter and collector;

means defining a substantially closed interaction chamber that includes said region between said emitter and collector, said interaction chamber being partially defined by two offset side walls that are respectively disposed on opposite lateral sides of said region;

a first venting means communicating with said interaction chamber adjacent the downstream end of one of said side walls;

a second venting means communicating -with said interaction chamber adjacent the downstream end of the other of said side walls;

said oflset side walls being laterally positioned relative to the axis of said emitter so that when said turbulent fluid flow condition exists in said region such flow will interact with both of 'said walls simultaneously and will exhaust to the surrounding atmosphere through both said rst and second venting means; and

control means for controlling the shifting of said fluid flow between said laminar and turbulent conditions.

41. Apparatus as defined by claim 40 -wherein at least the upstream portions of said |side walls extend substantially parallel to the axis of said emitter.

42. Apparatus as defined by claim 40 wherein at least the upstream end of said interaction chamber is rectangular in plan configuration and has laterally olset corners disposed on either side of the downstream end of said emitter.

43. Apparatus as defined by claim 40 -wherein the surfaces dening the upper walls of said emitter and interaction chamber are substantially coplanar.

44. Apparatus as defined by claim 43 wherein the depth of said interaction chamber is greater than the corresponding depth of said emitter.

45. A turbulence type amplifier: comprising a lower main plate member;

one face of said plate member having a first narrow elongated groove formed therein which effectively defines an emitter channel having a substantially rectangular cross sectional shape;

said face of the lower plate member being also formed with a second widened groove which communicates with said emitter channel so as to effectively define an interaction chamber having substantially rectangular sectional shapes at cross sections along the longitudinal axis thereof, the upstream portion of said interaction chamber presenting a substantial lateral set-back on both sides of the downstream end of said emitter channel;

said face of the lower main plate member having a further groove formed therein which communicates with said widened groove so as to effectively define a collector channel having a substantially rectangular cross sectional shape, said collector channel being disposed in substantially coaxial relation with respect to said emitter channel, the depth o'f said emitter and collector channels being less than that of said interaction chamber groove;

said emitter channel, collector channel and interaction chamber groove ybeing arranged so that alternate laminar and turbulent fiuid flow conditions may exist between said emitter and collector channels;

means defining a pair of venting holes disposed on opposite lateral sides of the downstream end lof said interaction chamber and through both of which holes fluid simultaneously flows when said fiuid flow condition is turbulent;

a cover plate having a substantially flat contact surface and secured in sealed relation to the grooved face of said lower plate member so as to close said grooves and thereby eifectively establish said channels and chamber; and

conduit means defining at least one control line operatively coupled to the said interaction chamber for controlling the shifting of the -fluid flow in said chamber between said turbulent and laminar conditions.

46. Apparatus as defined by claim 45 wherein said conduit means comprises a plurality of control grooves formed in said face of said lower main plate member and each communicating with said interaction chamber, the depth of each or said control grooves being less than that of said emitter channel.

47. Apparatus as defined by claim 45 wherein said emitter channel, collector channel and venting holes are substantially symmetrically disposed with respect to the axis of the plan profile of said interaction chamber.

48. Apparatus as defined by claim 45 wherein said interaction chamber includes a pair of laterally opposed side walls, said fluid fiow when turbulent simultaneously interacting with Iboth of said side -walls of said interaction chamber.

49. A fiuidic device: comprising an emitter adapted to issue a jet of uid;

a collector spaced from and operatively aligned with said emitter and adapted to receive fluid from said emitter;

means defining a substantially enclosed interaction chamber that includes the region between said emitter and collector;

said emitter, collector and interaction chamber being arranged so that alternate laminar and turbulent fluid flow conditions may exist in said region;

venting means for venting the downstream end of `said interaction c'hamber;

said interaction chamber being partially defined by laterally opposed side walls;

said interaction chamber being further partially defined by an upper surface which is substantially coplanar with the corresponding upper surface of said emitter and collector, and lbeing further partially defined by a bottom wall that is substantially lower than the corresponding bottom wall of said emitter whereby fluid issuing from said emitter may expand, when in a turbulent condition, downwardly as well as laterally in said interaction chamber and interact with both said side walls simultaneously in flowing to said venting means; and

control means for controlling the shifting of said uid -ow in said interaction chamber between said laminar and turbulent conditions.

50. Apparatus as defined by claim 49 wherein the effective depth of interaction chamber is up to four times the corresponding depth of said emitter.

References Cited UNITED STATES PATENTS 1,628,723 5/ 1927 Hall 137-815 XR 3,030,979 4/1962 Reilly IS7-81.5 3,148,691 9/ 1964 Greenblott 137-815 3,182,674 5/1965 Horton 137-815 3,182,675 5/ 1965 Zilberfarb et al. 137-81.5 3,187,763 6/1965 Adams 137-815 3,233,622 2/ 1966 Boothe I 137-815 3,234,955 2/1966 Auger 137-81.5 3,267,949 8/1966 Adams IS7-81.5 3,269,419 8/ 1966 Dexter 137-815 3,362,421 1/1968 Schaffer 137-81.5

OTHER REFERENCES Pneumatic Turbulence Amplifiers, R. N. Auger, Instrument and Control Systems, vol. 38, No. 3, March 1965, pp. 129, 130, 131-133.

SAMUEL SCOTT, Primary Examiner 

